By: Rahul Koul
Last updated : September 08, 2022 11:09 am
Customer expectations for customized and quality cement products driving full-fledged shift towards data oriented optimization of blending process
Maintaining a decent product quality besides predictable and consistent output during blending with third-party additives is a major challenge for the cement industry. The companies often struggle with the manual calculations required to blend the chemical characteristics and mining parameters. However, the state-of-the-art optimization technologies offered by the companies like Dassault Systemes are now helping them to make operational decisions accurately and consistently at all times.
“When I started my career 29 years back, the blending was only for the raw materials such as limestone or additives such as nitrite or iron ore. As the days passed, the quality of the fuel also deteriorated and blending material for fuel also had to be taken into consideration. Now after close to a decade, due to environmental requirements and usage of the recycled materials, the blending constraints have magnified to the extent that some of the fuels have added to complication. For us to do deal with these issues isn’t really simple blending related issue but the measurement itself,” said Sreekanth Reddy, Joint Managing Director, Sagar Cements Limited.
He spoke along with the other cement industry captains at the e-conference, ‘Blending Optimization for Cement Industry’ organized by the Indian Chemical Industry on September 06, 2022. The discussion was moderated by Pravin Prashant, Editor, ICN.
“The quality of the input material over years has deteriorated and there are a lot of restrictions that have been imposed by the mining regulations The limestone being a primary component and the ESG requirement only pushed us to ensure that most of the mines have a limited kind of rejection. This actually added to the complication as it made us invest quite a bit on the expert analytical systems. Our journey in this regard started 18 years back when we made investments into the analytical side and at the same time some of the software that gets associated with it. We started going within piling experts and then blending experts, especially the intermediate product, which is the clinker. But over the last two years, the requirement of expert solutions not just for quality of the clinker but for the end product also has gotten magnified, especially the end product material such as fly ash, slag etc. The requirement is not only for the technical aspects but even the financial model has become a necessity. It is heartening to know that Dassault Systemes has the product that includes both blending and financial components to it,” Reddy added.
“Earlier the cement plants used to produce in a limited way with products such as Portland pozzolana cement (PPC). But now there is an addition of various products like PCC, composite cement, slag cement and various types of other cement products that every company is coming out with. With that, the challenges have increased a lot. Whenever we fix any quality standards or assured quality norms (AQN) standards which are set district wise or state wise, a reverse planning has to be done. From the AQN that has to be followed to blending that is to be done in cement clinker grinding. Earlier we were using a single type of gypsum but now variety of gypsum, fly ash, and slack is being added into cement. As soon as you go reverse from clicker to raw mix, we were using 2-3 types of coal in the past but now with fluctuating prices, industry is shifting to indigenous pet coke or lignite. From raw mix to clinker production, the quality norms have to be set based on the alternate fuels which are based on different waste categories. Therefore, quality of fuel needs to be properly assessed,” said Saurabh Palsania, Group Commercial Head, Dalmia Cement (Bharat) Limited.
“With these challenges, there is also an opportunity before the industry to find out green materials that can fulfil the deficiency of alumina, iron or silica and to some extent limestone also. Varieties of limestone that are being used from various industries may reduce the cost and increase the options but adds to the challenge of maintaining the consistency of blends. With the increase of variety of cement products, variety of coal and additives as well as limestone and then quality of alternate fuels which can change minute by minute, are few of the biggest challenges. The solution providers such as Dassault Systemes will have to help the industry with the dynamics of fuel, additives as well as lime stone to achieve the standards amid continuous changeovers with the fuel mix and maintain the quality standards of cement as sought by customers,” added Palsania.
“We are mostly operating with the waste materials from the steel industry and we are using slack and iron flakes and also several other materials from the vegetable oil. All these things we are using as alternative raw materials and fuels. Because two decades back, we were having only two types of three types of cement blends but now to decrease the cost of production several blended materials are available. However, these too have changed from PPC to PSC and again to composite cement. To produce all these things requires a clinker and the clinker again requires raw materials. The raw materials costs, especially the product items cost has been increasing day by day. Therefore, we have used alternative material from our own steel company. There is a waste slack which is having a high alumina and it is a waste thrown outside. So now that we have started the recycling, it has reduced almost Rs 60 to Rs 70 per metric tonne of cement. We used other alternate fuels from chemical and pharma industries as well as agro waste which is available in plenty. The challenges are very high as the cement quality requirement is also increasing day by day in the market. The customer expectations in terms of color, strength and even far more than BIS standards. For that we have to have a very good clinker and C3S, C3A besides blended cement so as to meet their expectations,” said G. Veerababu, Chief Manufacturing Officer, JSW Limited.
“To address the challenges, we have just started using Dassault Systemes software at our plant and currently our team is undergoing the training to use it. It will go full-fledged in next few months,” Veerababu added further.
Talking about the solutions offered by his company, Chawki Jreige, Industry Process Senior Specialist, Dassault Systemes said, “Cement quarries need to buy the third party material in order to ensure consistent product. The mining sequence greatly determines which third party materials are required in any given period. Several mining parameters can be adjusted to tweak the mining sequence. The problem before us is which combination of mining parameters and third party materials will provide an acceptable schedule with the minimum additive costs. So what we did is that we took the customer data and optimized the schedule besides minimizing the additive cost.
Tactical blending provides optimization by iteration. It automates work-flows consisting of disparate applications. It provides you with the results of many runs to be able to make informed decisions. It is up to the planning engineer to tweak as per real life situations. The whole point of tactical blending is that we can provide the information so that clients are able to better optimize the schedule and minimize the additive costs.”
“Mineshed is a tactical scheduler that basically takes all of your data and allows the planning engineer to define mining rules such as production rates, directions, resource capacities. We then have a combined mindset with a simulation framework called Isight that comes from our sister brand, Simulia. Isight is a simulation framework and allows us to streamline the workflow. We define the inputs and we tell Isight which outputs to track. The simulation framework allows us to automate this process and create loops as many times as we want,” added Jreige.